体心立方（Body-centered cubic，BCC）点阵结构作为目前被广泛关注的点阵材料构型，其拓扑类型简单、SLM（Selective laser melting，SLM）成型可靠性好、压缩失效形式单一，但存在着承载能力相对较差的缺点。为探寻兼具轻质与高强性能的点阵构型，首先解除BCC点阵单胞各向尺寸相同的约束，提出体心四方（Body-centered tetragonal，BCT）点阵结构一般模型。然后，以BCT单胞构型尺寸为设计变量，以点阵材料尺寸与成型工艺为约束条件，以相对密度、初始刚度、塑性破坏强度为多目标评价函数，建立BCT点阵结构构型尺寸的多目标优化数学模型，采用理想点法求解得到BCT点阵单胞综合最优构型尺寸，并与BCC参照结构进行实例仿真对比分析，论证BCT优化结构相比BCC参照结构在性能上的优势。最后，采用Ti6Al4V材料通过SLM方法制备BCT优化结构与BCC参照结构的实验样件，并进行准静态单向压缩性能实验，验证理论分析结果的正确性，为轻质点阵结构材料的设计与研究提供了理论参考。
柏龙
,
熊飞
,
陈晓红
,
易长炎
,
张俊芳
,
陈锐
. SLM制备的Ti6Al4V轻质点阵结构多目标结构优化设计研究[J]. 机械工程学报, 2018
, 54(5)
: 156
-165
.
DOI: 10.3901/JME.2018.05.156
Taking advantages of simple type of topology, high manufacturing reliability and single form of compression failure, body-centered cubic (BCC) lattice structure has raised a widespread concern in recent years. However, it has the shortcoming of relatively poor bearing capacity. In order to explore a specific kind of lattice structure with light-weight and good mechanical properties, a body-centered tetragonal (BCT) lattice structure is proposed by removing the constraint of isotropy size in BCC lattice structure. A multi-objective optimization model for the configurational size of the BCT lattice structure is developed by taking the size of BCT cell configuration as the design variables, the size of lattice material and manufacturing process as the constraints, and the relative density, the initial stiffness and the strength of plastic collapse as the multi-objective evaluation functions. Based on the optimization model, the optimal configuration dimension of BCT lattice cell is obtained by using the ideal point method. The performance advantages of the optimized BCT structure are proved by comparing with the BCC reference structure through simulation analysis. Finally, the experimental samples of the optimized BCT structure and BCC reference structure are fabricated by selective laser melting (SLM) using the material of Ti6Al4V. The quasi-static uniaxial compression experiment is conducted and the theoretical analysis results are verified. The theoretical and experimental results have general applicability to the design and research of the light-weight lattice structure materials.
[1] EVANS A G,HUTCHINSON J W,FLECK N A,et al. The topological design of multifunctional cellular metals[J]. Progress in Materials Science,2001,46:309-327.
[2] 方岱宁,张一慧,崔晓东. 轻质点阵材料力学与多功能设计[M]. 北京:科学出版社,2009. FANG Daining,ZHANG Yihui,CUI Xiaodong. The design of mechanical properties and multifunction of lightweight lattice[J]. Beijing:Science Press,2009.
[3] 卢天健,何德坪,陈常青,等. 超轻多孔金属材料的多功能特性及应用[J]. 力学进展,2006,36(4):517-535. LU Tianjian,HE Deping,CHEN Changqing,et al. The multifunction characteristic and the apply of the lightweight porous metallic material[J]. Advances in Mechanics,2006,36(4):517-535.
[4] 陈继伟. 超轻点阵材料的研究进展[J]. 装备制造技术,2014(9):229-230. CHEN Jiwei. The research progress of ultralight lattice structures[J]. Equipment Manufacturing Technology,2014(9):229-230.
[5] 敬霖,赵永翔. 轻量化多孔金属夹芯复合板的耐撞性[J]. 机械工程学报,2014,50(16):1-5. JING Lin,ZHAO Yongxiang. Crashworthiness of light-weight sandwich panels with cellular metallic cores[J]. Journal of Mechanical Engineering,2014,50(16):1-5.
[6] 曾嵩,朱荣,姜炜,等. 金属点阵材料的研究进展[J]. 材料导报,2012,26(3):18-23. ZENG Song,ZHU Rong,JIANG Wei,et al. Research progress of metal lattice materials[J]. Materials Review,2012,26(3):18-23.
[7] MASKERY I,AREMU A O,SIMONELLI M,et al. Mechanical properties of Ti-6Al-4V selectively laser melted parts with body-centred-cubic lattices of varying cell size[J]. Experimental Mechanics,2015,55(7):1261-1272.
[8] LEARY M,MAZUR M,ELAMBASSERIL J,et al. Selective laser melting (SLM) of AlSi12Mg lattice structures[J]. Materials and Design,2016,98:344-357.
[9] QIU C,YUE S,ADKINS N J E,et al. Influence of processing on strut structure and compressive properties of cellular lattice structures fabricated by selective laser melting[J]. Materials Science & Engineering A,2015,628:188-197.
[10] MCKOWN S,SHEN Y. The quasi-static and blast loading response of lattice structures[J]. International Journal of Impact Engineering,2008,35(8):795-810.
[11] USHIJIMA K,CANTWELL W J,MINES R A W,et al. An investigation into the compressive properties of stainless steel micro-lattice structures[J]. Journal of Sandwich Structures and Materials,2010,13(3):303-329.
[12] TSOPANOS S,MINES R A W,MCKOWN S,et al. The influence of processing parameters on the mechanical properties of selectively laser melted micro-lattice structures[J]. Journal of Manufacturing Science and Engineering,2010,132:041011-1-041011-12.
[13] REHME O,EMMELMANN C. Rapid manufacturing of lattice structures with selective laser melting[J]. Proc. of SPIE,2006,6107(1):1-12.
[14] MERKT S,HINKE C,BULTMANN J,et al. Mechanical response of TiAl6V4 lattice structures manufactured by selective laser melting in quasistatic and dynamic compression tests[J]. Journal of Laser Applications,2015,27(1):S17006-1-S17006-6.
[15] WALLACH J,GIBSON L J. Mechanical behavior of a three-dimensional truss material[J]. International Journal of Solids and Structures,2001,38(40):7181-7196.
[16] PEIFENG L. Constitutive and failure behaviour in selective laser melted stainless steel for microlattice structures[J]. Materials Science & Engineering A,2015,622:114-120.
[17] MAZUR M,LEARY M,SUN S,et al. Deformation and failure behaviour of Ti-6Al-4V lattice structures manufactured by selective laser melting (SLM)[J]. Int. J. Adv. Manuf. Technol.,2016,84(5):1391-1411.
[18] 范华林,杨卫. 轻质高强点阵材料及其力学性能研究进展[J]. 力学进展,2007,37(1):99-112. FAN Hualin,YANG Wei. The research progress of lightweight high strength lattice materials and mechanical properties[J]. Advances In Mechanics,2007,37(1):99-112.
[19] GUMRUK R,MINES R. Compressive behavior of stainless steel micro-lattice structures[J]. International Journal of Mechanical Sciences,2013,68:125-139.
[20] 张升,桂睿智,魏青松,等. 选择性激光熔化成形TC4钛合金开裂行为及其机理研究[J]. 机械工程学报,2013,49(23):21-27. ZHANG Sheng,GUI Ruizhi,WEI Qingsong,et al. Cracking behavior and formation mechanism of TC4 alloy formed by selective laser melting (SLM)[J]. Journal of Mechanical Engineering,2013,49(23):21-27.
[21] GIBSON L J,ASHBY M. 多孔固体结构与性能[M]. 北京:清华大学出版社,2003. GIBSON L J,ASHBY M. Celluar solids structure and properties[M]. Beijing:Tsinghua University Press,2003.
